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Electronic Flora of South Australia
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Electronic Flora of South Australia species Fact Sheet

Family: Labiatae
Prostanthera chlorantha

Citation: F. Muell. ex Benth., Fl. Aust. 5:108 (1870).

Synonymy: Klanderia chlorantha F. Muell., Linnaea 25:426 (1853).

Common name: Green mintbush.

Small shrub, to 0.5 rarely 1 m high; branches with irregularly branched or occasionally simple 0.1-0.4 mm long hairs, branches sparsely glandular; leaves mostly arranged along short side branches, with branched hairs; petiole absent or less than 0.5 mm long; lamina suborbicular to broadly ovate, 1-3 mm long, 1-2.5 rarely 3 mm wide; base rounded; margin entire, strongly recurved especially towards the base and so the lamina appearing triangular; apex obtuse to rounded; venation not visible to indistinct.

Pedicel 5-13 mm long, slender, often glabrous basally, glabrescent for much of its length, distally with branched hairs, sparsely glandular; bracteoles inserted 0.5-3 mm from the distal end of the pedicel, narrowly obovate, 1-2 mm long, c. 0.5 mm wide; calyx 8-12 mm long, green, often with red-purple ribs or streaks, especially on the tube; outer surface tomentose with branched hairs and scaly; inner surface glabrous; tube 5-6 mm long; lobes triangular, 3-6 mm long, 2-4 mm wide; corolla 15-25 mm long, mauve, blue-green, a dusty green-red to green-yellow with a pink tinge; outer surface sparsely hairy distally with simple c. 0.1 mm long hairs; inner surface lacking dark spots, glabrous; tube 10-25 mm long; lower median lobe obovate, 2-5 mm long, c. 2 mm wide, slightly recurved; lateral lobes oblong-ovate, 4-5 mm long, c. 2 mm wide; upper median lobe-pair suborbicular to broadly ovate, 5-10 mm long, c. 10 mm wide, slightly recurred distally; stamens inserted c. 10 mm above the base of the corolla; filaments c. 5 mm long, with minute triangular glandular trichomes; anthers 1.5-2 mm long; although appendage appearing absent, one side of the connective usually slightly extended to form a minute basal appendage to 0.03 mm long, sometimes with minute triangular tichomes present; pistil 17-22 mm long; ovary c. 0.5 mm long; style 15-18 mm long; stigma lobes to 1 mm long.

Fruiting calyx only slightly enlarged; mericarps 2-3 mm long.

image of FSA3_Prostanthera_chl.jpg
Image source: fig. 556A in Jessop J.P. & Toelken H.R. (Ed.) 1986. Flora of South Australia (4th edn).

Published illustration: Althofer (1978) Cradle of incense, p. 128.

Distribution:  This species forms small populations of a few scattered plants, on sandy and loamy soils. It is commonly associated with Banksia, Daviesia and Leptospermum shrubland.

S.Aust.: EP, MU, SL, KI.

Conservation status: native

Flowering time: Aug. — Jan.

SA Distribution Map based
on current data relating to
specimens held in the
State Herbarium of South Australia

Biology: No text

Taxonomic notes: This species is readily identified by the presence of irregularly branched hairs. P. serpyllifolia (R. Br.)Briq. Subsp. microphylla (R. Br.) Conn (from KI) is the only other taxon which has irregularly branched hairs, but these only occur on the calyx. This species appears to be endangered from a conservation point of view.

Author: Not yet available

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